Fig. 5
From: Alpha shapes: determining 3D shape complexity across morphologically diverse structures
The stepped alpha-shape profile of a canid baculum (modelled in 2-dimensions for illustrative purposes). Circles illustrate the value of alpha radius at four locations (a-d) along the alpha curve. The step between b and c represents the point at which the alpha exceeds the width of the urethral groove. Once the groove is no longer distinguished, alpha volume increases dramatically